语法与词汇 3.If not properly______, border issues which are always very sensitive and complicated international relations can often trigger conflicts.

A、 handled
B、 handing
C、 handle
D、 to handle

【正确答案】 A

【答案解析】本题考查if引导的状语从句的省略。if从句的主语与主句的主语一致，都为border issues，且从句主语后跟有动词be，通常可以省略if从句中的“主语+be”。从句的完整形式为：If border issues are not properly handled，…。故答案为handled。